1. Field
An aspect of the invention relates to a mobile device that has, for example, a housing defining a battery chamber in which a battery is loaded, and a battery lid covering the battery chamber so as to be freely detached, and that runs on power supplied from the battery loaded in the battery chamber.
2. Description of the Related Art
Recently, the use of mobile devices such as mobile phones and handheld video game machines has greatly increased. Most of such mobile devices have batteries loaded therein and run on power supplied from the batteries.
While these mobile devices such as mobile phones incorporate more sophisticated functions, the device size and weight are further reduced. Nowadays, there is also a demand for a waterproof function. Where the waterproof function is incorporated in the mobile device that has a housing in which a large opening is defined for the battery chamber for loading the battery therein, rendering the battery chamber waterproof poses a problem.
For example, Japanese Laid-open Patent Publication No. 2004-56164 discloses rendering a battery pack storage section waterproof by means of an O-ring and an inner cover. Japanese Laid-open Patent Publication No. 11-25940 discloses rendering a battery pocket waterproof by means of a battery lid and waterproof packing.
In this case, it is important to render the battery chamber and its periphery waterproof without increasing the size and weight of the mobile device. Generally, a battery chamber and its periphery are rendered waterproof by fixing packing or an O-ring inside the lid which covers the battery chamber, and by pressing the packing or O-ring against the edges of the battery chamber. In this case, it is necessary that the packing or O-ring be pressed against the edges of the battery chamber without being twisted, specifically, it is necessary that force is applied only in the direction in which the packing or O-ring is pressed against the edges, not sideways to the packing or O-ring. To achieve this, it is best to depress the lid from directly above the battery chamber. However, depressing the lid from directly above the battery chamber, while keeping the lid and body joined, requires a complicated structure. This frustrates the demand for a more compact design. Employing a structure in which the lid which covers the battery chamber is pivotally supported by the body so as to be freely opened or closed around a rotation shaft extending along one side of the lid may produce sideways force in the packing or O-ring disposed inside the lid. A design taking account of such sideways force such that this sideways force is not varied by a user closing the lid may keep the sideways force within permissible levels. However, in this case, a structure in which the rotation shaft is pivotally supported by the body so as to be freely rotated may increase the size of the mobile device.
To make the mobile device more compact, it is preferable that the lid can be completely separated from the body. In this case, sideways force acting on the packing or O-ring disposed inside the lid may be varied according to subtle changes in the manner in which the lid is closed by a user. Therefore, how to always keep the sideways force, that is, torsion of the packing or O-ring within permissible levels poses a problem.